Electro-hydraulic control system using shift valves for a hybrid drive unit

ABSTRACT

A valve body assembly for a hybrid drive unit includes a pressure regulator valve, a first on/off shift valve for controlling a stationary clutch, a second on/off shift valve for controlling a rotating clutch, and a third on/off shift valve for controlling a damper bypass clutch. The control system controls the stationary clutch and the rotating clutch to operate the hybrid drive unit in four different modes. The first shift valve, the second shift valve and the third shift valve do not include a regulated pressure feedback port, nor a pressure switch for indicating a clutch fill level.

TECHNICAL FIELD

The invention generally relates to a control system for controlling ahybrid drive unit.

BACKGROUND

Hybrid vehicles typically include one or more electric motors and anengine for generating a torque, and a hybrid drive unit, i.e., atransmission, for routing the torque to at least one wheel through aplurality of different gear sets. The hybrid drive unit typicallyincludes a plurality of planetary gear sets, each including a pluralityof gear members. The hybrid drive unit also includes a plurality ofdifferent torque transmitting devices, such as clutches and brakes thatare configured for selectively interconnecting the engine and/or theelectric motors with various members of the planetary gear sets.

A control system controls the operation of the hybrid drive unit. Thecontrol system includes a valve body assembly having a plurality ofhydraulic valves housed in a valve body and configured for actuating,i.e., engaging or disengaging, the various torque transmitting devicesto route the torque through different power flow paths to providedifferent operating modes. Additionally, the valve body assemblycontrols fluid flow for cooling and/or lubricating the variouscomponents of the vehicle, such as the gear sets and the electricmotor(s).

SUMMARY

A control system for controlling a hybrid drive unit of a vehicle isprovided. The control system includes a pressure regulator valve influid communication with a plurality of fluid lines. The pressureregulator valve regulates a line pressure of a fluid within theplurality of fluid lines. A first valve is disposed in fluidcommunication with at least one of the plurality of fluid lines. Thefirst valve opens and closes fluid communication between the pluralityof fluid lines and a first clutch for engaging and disengaging the firstclutch respectively. A second valve is disposed in fluid communicationwith at least one of the plurality of fluid lines. The second valveopens and closes fluid communication between the plurality of fluidlines and a second clutch for engaging and disengaging the second clutchrespectively. The first valve disengages the first clutch and the secondvalve disengages the second clutch to operate the hybrid drive unit in afirst mode. The first valve engages the first clutch and the secondvalve disengages the second clutch to operate the hybrid drive unit in asecond mode. The first valve engages the first clutch and the secondvalve engages the second clutch to operate the hybrid drive unit in athird mode. The first valve disengages the first clutch and the secondvalve engages the second clutch to operate the hybrid drive unit in afourth mode. The first valve and the second valve each include a shiftvalve characterized by a lack of a regulated pressure feedback port.

A valve body assembly for controlling a hybrid drive unit of a vehicleis also provided. The valve body assembly includes a pressure regulatorvalve in fluid communication with a plurality of fluid lines. Thepressure regulator valve regulates a line pressure of a fluid within theplurality of fluid lines. A first electronically controlled hydraulicvalve is disposed in fluid communication with at least one of theplurality of fluid lines. The first electronically controlled hydraulicvalve opens and closes fluid communication between the plurality offluid lines and a first clutch for engaging and disengaging the firstclutch respectively. A second electronically controlled hydraulic valveis disposed in fluid communication with at least one of the plurality offluid lines. The second electronically controlled hydraulic valve opensand closes fluid communication between the plurality of fluid lines anda second clutch for engaging and disengaging the second clutchrespectively. A third electronically controlled hydraulic valve isdisposed in fluid communication with at least one of the plurality offluid lines. The third electronically controlled hydraulic valve opensand closes fluid communication between the plurality of fluid lines anda third clutch for engaging and disengaging the third clutchrespectively. A fourth electronically controlled hydraulic valve isdisposed in fluid communication with at least one lubrication circuitand the pressure regulator valve. The fourth electronically controlledhydraulic valve regulates a flow of the fluid between the pressureregulator valve and the at least one lubrication circuit. The firstvalve disengages the first clutch and the second valve disengages thesecond clutch to operate the hybrid drive unit in a first mode. Thefirst valve engages the first clutch and the second valve disengages thesecond clutch to operate the hybrid drive unit in a second mode. Thefirst valve engages the first clutch and the second valve engages thesecond clutch to operate the hybrid drive unit in a third mode. Thefirst valve disengages the first clutch and the second valve engages thesecond clutch to operate the hybrid drive unit in a fourth mode. Thefirst valve, the second valve and the third valve each include a shiftvalve characterized by a lack of a regulated pressure feedback port. Thefirst valve, the second valve and the third valve are each characterizedby the lack of a pressure switch for indicating a clutch fill level.

The above features and advantages and other features and advantages ofthe present invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The Figure is a schematic diagram of a control system for a hybrid driveunit.

DETAILED DESCRIPTION

Referring to the Figure, a control system is shown generally at 20. Thecontrol system 20 controls the operation of a hybrid drive unit of avehicle.

The hybrid drive unit, i.e., a transmission for a hybrid vehicle,includes a plurality of clutches configured for interconnecting, invarious combinations, a first electric motor 22, a second electric motor24 and an engine, with a plurality of gear sets. The engine may includeany type of engine suitable for use in a hybrid vehicle. For example,the engine includes an internal combustion engine. However, it should beappreciated that the engine may include some other type of engine notdescribed herein. The specific type, size, shape and/or configuration ofthe engine is not relevant to the description of the invention, andtherefore is not described in detail herein. The first electric motor 22and the second electric motor 24 may include any suitable type, size,shape and/or configuration of electric motor suitable for use in ahybrid vehicle. The specific type, size shape and/or configuration ofthe first electric motor 22 and the second electric motor 24 are notrelevant to the description of the invention, and therefore are notdescribed in detail herein.

As described herein, the hybrid drive unit includes a first clutch and asecond clutch. The first clutch includes a stationary clutch 26, and thesecond clutch includes a rotating clutch 28. The hybrid drive unitoperates in four modes: a first mode hereinafter referred to as anElectronic Torque Converter (ETC) mode, a second mode hereinafterreferred to as a low mode, a third mode hereinafter referred to as afixed gear mode, and a fourth mode hereinafter referred to as a highmode. When in the ETC mode, the first clutch and the second clutch areboth disengaged. When in the low mode, the first clutch is engaged andthe second clutch is disengaged. When in the fixed gear mode, both thefirst clutch and the second clutch are engaged. When in the high mode,the first clutch is disengaged and the second clutch is engaged. The lowmode provides lower gear ratios for operating the hybrid drive unit atlower speeds, while the high mode provides higher gear ratios foroperating the hybrid drive unit at higher speeds.

The hybrid drive unit further includes a third clutch, hereinafterreferred to as a damper bypass clutch 30. The damper bypass clutch 30directly interconnects the hybrid drive unit and the engine. The damperbypass clutch 30 is engaged to directly connect the hybrid drive unitand the engine when starting the engine. When engaged, the damper bypassclutch 30 provides a fixed connection between the engine and the hybriddrive unit. When disengaged, the damper bypass clutch 30 allows thehybrid drive unit to torsionally flex relative to the engine through aplurality of damper springs as is known.

A pump 32 pressurizes and circulates a fluid through the hybrid driveunit and the control system 20. The pump 32 may include any suitabletype and/or size of pump 32 capable of providing sufficient flow andpressure. The specific type, size and/or configuration of the pump 32are not relevant to the description of the invention, and is thereforenot described in detail herein.

Referring to the Figure, the control system 20 includes a valve bodyassembly 33 that is coupled to the hybrid drive unit. The valve bodyassembly 33 includes, but is not limited to, a pressure regulator valve34, a first valve hereinafter referred to as a stationary clutch valve36, a second valve hereinafter referred to as a rotating clutch valve38, a third valve hereinafter referred to as a damper bypass valve 40, afourth valve hereinafter referred to as a lube regulator valve 42 and acompensator feed valve 44.

The stationary clutch valve 36, the rotating clutch valve 38 and thedamper bypass valve 40 each include a shift valve. The shift valves 36,38, 40 are actuated between an “on” position and an “off” position. Theshift valves 36, 38, 40 are characterized by the lack of a regulatedpressure feedback port that directs fluid pressure from a control signaloutput to an end of the valve, thereby differentiating the shift valves36, 38, 40 from pressure regulator valves. The shift valves 36, 38, 40are further characterized by the lack of a pressure switch forindicating a clutch fill level, thereby further differentiating theshift valves 36, 38, 40 from the pressure regulator valves. The shiftvalves are each actuated by an “on/off” solenoid to move between the onposition and the off position.

The pump 32 pressurizes the fluid to a line pressure, and circulates thefluid at the line pressure to the damper bypass valve 40, the stationaryclutch valve 36, the rotating clutch valve 38, the compensator feedvalve 44, the pressure regulator valve 34, the lube regulator valve 42,an on/off solenoid 92, an on/off solenoid 114, an on/off solenoid 76, amini direct acting solenoid 60, and a lube boost solenoid 142.Accordingly, the pump 32 is in direct fluid communication with thedamper bypass valve 40, the stationary clutch valve 36, the rotatingclutch valve 38, the compensator feed valve 44, the pressure regulatorvalve 34, the lube regulator valve 42, the on/off solenoid 92, theon/off solenoid 114, the on/off solenoid 76, the mini direct actingsolenoid 60, the lube boost solenoid 142 through a system of highpressure fluid lines and/or passages in the valve body.

The valve body further includes a line blow-off 46. The line blow-off 46is a pressure sensitive valve that opens in response to the linepressure reaching a pre-determined level. The line blow-off 46 preventsdamage to the control system 20 and/or the hybrid drive unit by openingthe line pressure to the atmosphere in response to the line pressurereaching a dangerously high level.

A primary feed pressure line 48 interconnects the pump 32 and thepressure regulator valve 34 to provide the fluid to the pressureregulator valve 34 at the line pressure. A suction return line 50interconnects the pressure regulator valve 34 with a sump portion of thepump 32 for directing fluid back to the pump 32 to reduce the linepressure. The pressure regulator valve 34 includes a spool portion 52that is moveable between a first position, a second position and a thirdposition. The primary feed pressure line 48 includes a feed line 54 anda feedback line 56 for providing the fluid to the spool portion 52 atthe line pressure. The feedback line 56 acts against an end of the spoolportion 52 of the pressure regulator valve 34 to bias against the spoolportion 52.

When in the first position, the pressure regulator valve 34 operates tomaintain the existing line pressure. When in the first position, thespool portion 52 of the pressure regulator valve 34 prevents fluid flowfrom the feed line 54 from flowing back to the pump 32 via the suctionreturn line 50, and also prevents fluid flow to the lube regulator valve42 via a lube feed line 122, which interconnects the pressure regulatorvalve 34 and the lube regulator valve 42.

When in the second position, which is shown in the Figure, the spoolportion 52 of the pressure regulator valve 34 opens fluid communicationbetween the feed line 54 and lube feed line 122 to supply the luberegulator valve 42 with fluid at the line pressure, while stillpreventing fluid communication between the feed line 54 and the suctionreturn line 50. The pressure regulator valve 34 moves into the secondposition in response to the fluid pressure reaching a minimum supplypressure, which is the level required to supply all priority operationsof the control system 20. The priority operations of the control system20 include supplying the damper bypass valve 40, the stationary clutchvalve 36, the rotating clutch valve 38 and the compensator feed valve 44with fluid at the line pressure. Once the priority operations of thecontrol system 20 are satisfied, the pressure regulator valve 34 maymove into the second position to supply the lube regulator valve 42,which is a secondary operation of the control system 20.

When in the third position, the spool portion 52 of the pressureregulator valve 34 maintains fluid communication between the feed line54 and the lube feed line 122, while opening fluid communication betweenthe feed line 54 and the suction return line 50. The pressure regulatorvalve 34 moves into the third position when the line pressure exceeds amaximum allowable pressure. When in the third position, the fluid isdirected from the feed line 54 to the sump portion of the pump 32 toreduce the line pressure. Once the line pressure is reduced to anacceptable level, the pressure regulator valve 34 may move back intoeither the second position or the first position.

The pressure regulator valve 34 is controlled by the Mini Direct Acting(MDA) solenoid 60 in fluid communication with the primary feed pressureline 48. It should be appreciated that the solenoid 60 may include anysuitable type of solenoid capable of controlling the spool portion 52 ofthe pressure regulator valve 34. The solenoid 60 of the pressureregulator valve 34 utilizes an electrical signal from a hybrid driveunit controller or a vehicle controller to open and close fluidcommunication from the primary feed pressure line 48 to an end of thespool portion 52 of the pressure regulator valve 34 to actuate the spoolportion 52 of the pressure regulator valve 34. As such, the pressureregulator valve 34 is an electronically controlled hydraulic valve.

A pressure regulator signal line 62 interconnects the solenoid 60 of thepressure regulator valve 34 with an end of the spool portion 52 of thepressure regulator valve 34. The pressure regulator signal line 62provides a fluid pressure, which acts against the spool portion 52 ofthe pressure regulator valve 34 to bias the spool portion 52 of thepressure regulator valve 34 against the fluid pressure provided by thefeedback line 56 of the pressure regulator valve 34. The solenoid 60 ofthe pressure regulator valve 34 controls the fluid pressure of thepressure regulator signal line 62 to control movement of the spoolportion 52 of the pressure regulator valve 34 between the firstposition, the second position and the third position. By reducing thefluid pressure of the pressure regulator signal line 62, the spoolportion 52 of the pressure regulator valve 34 moves from the firstposition toward the second and/or the third position. By increasing thefluid pressure of the pressure regulator signal line 62 to the linepressure, the pressure regulator signal line 62, in combination with aregulator spring 64, move the spool portion 52 of the pressure regulatorvalve 34 into the first position.

The solenoid 60 of the pressure regulator valve 34 is normally open, ornormally high, to maintain the fluid pressure of the pressure regulatorsignal line 62 at the line pressure to move the spool portion 52 of thepressure regulator valve 34 into the first position. The solenoid 60 ofthe pressure regulator valve 34 closes, or reduces the fluid pressure ofthe pressure regulator signal line 62 as the line pressure increases toabove the minimum supply pressure and/or the maximum allowable pressureto move the spool portion 52 into the second position or the thirdposition to regulate the line pressure.

The primary feed pressure line 48 interconnects the pump 32 and thedamper bypass valve 40 to provide the fluid to the damper bypass valve40 at the line pressure. A damper control line 68 interconnects thedamper bypass valve 40 and the damper bypass clutch 30. The damperbypass valve 40 includes a spool portion 72 that is moveable between anopen position and a closed position. When in the closed position, whichis shown in the Figure, the spool portion 72 of the damper bypass valve40 prevents fluid communication between the primary feed pressure line48 and the damper control line 68 to prevent engagement of the damperbypass clutch 30, and exhausts fluid pressure from the damper controlline 68 via an exhaust line 74 to disengage the damper bypass clutch 30.When in the open position, the spool portion 72 of the damper bypassvalve 40 opens fluid communication between the primary feed pressureline 48 and the damper control line 68 to provide fluid to the damperbypass clutch 30 at the line pressure to engage the damper bypass clutch30. Additionally, when in the open position, the spool portion 72 closesfluid communication between the damper bypass valve 40 and the exhaustline 74 to prevent disengagement of the damper bypass clutch 30.

The damper bypass valve 40 is controlled by the on/off solenoid 76. Itshould be appreciated that the on/off solenoid 76 may include anysuitable type of solenoid capable of controlling the damper bypass valve40. The solenoid 76 of the damper bypass valve 40 is in fluidcommunication with the primary feed pressure line 48 and utilizes anelectrical signal from the hybrid drive unit controller or the vehiclecontroller to open and close fluid communication between the primaryfeed pressure line 48 and a damper bypass signal line 78. Accordingly,the damper bypass valve 40 is an electronically controlled hydraulicvalve.

The damper bypass signal line 78 interconnects the solenoid 76 of thedamper bypass valve 40 with a second end of the spool portion 72 of thedamper bypass valve 40. The damper bypass signal line 78 provides afluid pressure, which acts against the spool portion 72 of the damperbypass valve 40 to bias the spool portion 72 of the damper bypass valve40 against a damper spring 80. The solenoid 76 of the damper bypassvalve 40 controls the fluid pressure of the damper bypass signal line 78to control movement of the spool portion 72 of the damper bypass valve40 between the open position and the closed position. By increasing thefluid pressure of the damper bypass signal line 78 to the line pressure,the damper bypass signal line 78 overcomes the reactionary forceprovided by the damper spring 80, to move the spool portion 72 of thedamper bypass valve 40 into the open position. By decreasing the fluidpressure of the damper bypass signal line 78, the damper spring 80 mayovercome the pressure from the damper bypass signal line 78 and move thespool portion 72 into the closed position, thereby opening fluidcommunication with the exhaust line 74 and disengaging the damper bypassclutch 30. The solenoid 76 of the damper bypass valve 40 is normallyclosed, or normally low, to position the spool portion 72 of the damperbypass valve 40 in the closed position with the damper bypass clutch 30disengaged. The solenoid 76 of the damper bypass valve 40 increasesfluid pressure in the damper bypass signal line 78 when directed toengage the damper bypass clutch 30.

The primary feed pressure line 48 interconnects the pump 32 and thestationary clutch valve 36 to provide the fluid to the stationary clutchvalve 36 at the line pressure. A stationary clutch control line 84interconnects the stationary clutch valve 36 and the stationary clutch26. The stationary clutch valve 36 includes a spool portion 88 that ismoveable between an open position and a closed position. When in theclosed position, which is shown in the Figure, the spool portion 88 ofthe stationary clutch valve 36 prevents fluid communication between theprimary feed pressure line 48 and the stationary clutch control line 84to prevent engagement of the stationary clutch 26, and exhausts fluidpressure from the stationary clutch control line 84 via the exhaust line90 to disengage the stationary clutch 26. When in the open position, thespool portion 88 of the stationary clutch valve 36 opens fluidcommunication between the primary feed pressure line 48 and thestationary clutch control line 84 to provide fluid to the stationaryclutch 26 at the line pressure to engage the stationary clutch 26.Additionally, when in the open position, the spool portion 88 of thestationary clutch valve 36 closes fluid communication between thestationary clutch control line 84 and the exhaust line 90 to preventdisengagement of the stationary clutch 26.

The stationary clutch valve 36 is controlled by the on/off solenoid 92.It should be appreciated that the on/off solenoid 92 may include anysuitable type of solenoid capable of controlling the spool portion 88 ofthe stationary clutch valve 36. The solenoid 92 of the stationary clutch26 is in fluid communication with the primary feed pressure line 48, andutilizes an electrical signal from the hybrid drive unit controller orthe vehicle controller to open and close fluid communication between theprimary feed pressure line 48 and a stationary clutch signal line 94.Accordingly, the stationary clutch valve 36 is an electronicallycontrolled hydraulic valve.

The stationary clutch signal line 94 interconnects the solenoid 92 ofthe stationary clutch valve 36 with a second end of the spool portion 88of the stationary clutch valve 36. The stationary clutch signal line 94provides a fluid pressure, which acts against the spool portion 88 ofthe stationary clutch valve 36 to bias the spool portion 88 of thestationary clutch valve 36 against a stationary clutch spring 96. Thesolenoid 92 of the stationary clutch valve 36 controls the fluidpressure of the stationary clutch signal line 94 to control movement ofthe spool portion 88 of the stationary clutch valve 36 between the openposition and the closed position. By increasing the fluid pressure ofthe stationary clutch signal line 94 to the line pressure, thestationary clutch signal line 94 overcomes the reactionary forceprovided by the stationary clutch spring 96, to move the spool portion88 of the stationary clutch valve 36 into the open position. Bydecreasing the fluid pressure of the stationary clutch signal line 94the stationary clutch spring 96 may overcome the pressure from thestationary clutch signal line 94 and move the spool portion 88 into theclosed position, thereby opening fluid communication with the exhaustline 90 and disengaging the stationary clutch 26. The solenoid 92 of thestationary clutch valve 36 is normally closed, or normally low, toposition the spool portion 88 of the stationary clutch valve 36 in theclosed position with the stationary clutch 26 disengaged. The solenoid92 of the stationary clutch valve 36 increases fluid pressure in thestationary clutch signal line 94 when directed to engage the stationaryclutch 26.

An accumulator 98 is in fluid communication with the stationary clutchcontrol line 84. The accumulator 98 dampens hydraulic shock within thesystem caused by movement of the fluid between the stationary clutch 26and the stationary clutch valve 36.

The primary feed pressure line 48 interconnects the pump 32 with therotating clutch valve 38 and the compensator feed valve 44. The primaryfeed pressure line 48 provides the fluid to the rotating clutch valve 38and the compensator feed valve 44 at the line pressure. The compensatorfeed valve 44 provides a fluid back pressure to the rotating clutch 28through the rotating clutch valve 38. A compensator supply line 102interconnects the compensator feed valve 44 with the rotating clutchvalve 38, and a compensator feed line 104 interconnects the rotatingclutch valve 38 with a backside of the rotating clutch 28. Thecompensator feed valve 44 may include any type of valve suitable forregulating the fluid backpressure for the rotating clutch 28.

A rotating clutch control line 106 interconnects the rotating clutchvalve 38 and the rotating clutch 28. The rotating clutch valve 38includes a spool portion 110 that is moveable between an open positionand a closed position. When in the closed position, which is shown inthe Figure, the spool portion 110 of the rotating clutch valve 38prevents fluid communication between the primary feed pressure line 48and the rotating clutch control line 106 to prevent engagement of therotating clutch 28, and exhausts fluid pressure from the rotating clutchcontrol line 106 via an exhaust line 112 to disengage the rotatingclutch 28. Additionally, when in the closed position, the rotatingclutch valve 38 opens fluid communication between the compensator supplyline 102 and the compensator feed line 104 to permit fluid flow to theback side of the rotating clutch 28. When in the open position, thespool portion 110 of the rotating clutch valve 38 opens fluidcommunication between the primary feed pressure line 48 and the rotatingclutch control line 106 to provide fluid to the rotating clutch 28 atthe line pressure to engage the rotating clutch 28. Furthermore, when inthe open position, the spool portion 110 of the rotating clutch valve 38closes fluid communication between the rotating clutch control line 106and the exhaust line 112 to prevent disengagement of the rotating clutch28. Additionally, when in the open position, the rotating clutch valve38 closes fluid communication between the compensator supply line 102and the compensator feed line 104 to limit and/or prevent fluidcommunication with the back side of the rotating clutch 28, which wouldotherwise act against the line pressure being applied to the rotatingclutch 28 when the rotating clutch valve 38 is in the open position.

The rotating clutch valve 38 is controlled by the on/off solenoid 114.It should be appreciated that the on/off solenoid 114 may include anysuitable type of solenoid capable of controlling the spool portion 110of the rotating clutch valve 38. The solenoid 114 of the rotating clutch28 is in fluid communication with the primary feed pressure line 48, andutilizes an electrical signal from the hybrid drive unit controller orthe vehicle controller to open and close fluid communication between theprimary feed pressure line 48 and a rotating clutch signal line 116.Accordingly, the rotating clutch valve 38 is an electronicallycontrolled hydraulic valve.

The rotating clutch signal line 116 interconnects the solenoid 114 ofthe rotating clutch valve 38 with a second end of the spool portion 110of the rotating clutch valve 38. The rotating clutch signal line 116provides a fluid pressure, which acts against the spool portion 110 ofthe rotating clutch valve 38 to bias the spool portion 110 of therotating clutch valve 38 against a rotating clutch spring 118. Thesolenoid 114 of the rotating clutch valve 38 controls the fluid pressureof the rotating clutch signal line 116 to control movement of the spoolportion 110 of the rotating clutch valve 38 between the open positionand the closed position. By increasing the fluid pressure of therotating clutch signal line 116 to the line pressure, the rotatingclutch signal line 116 overcomes the reactionary force provided by therotating clutch spring 118, to move the spool portion 110 of therotating clutch valve 38 into the open position. By decreasing the fluidpressure of the rotating clutch signal line 116, the rotating clutchspring 118 may overcome the pressure from the rotating clutch signalline 116 and move the spool portion 110 into the closed position,thereby opening fluid communication with the exhaust line 112 anddisengaging the rotating clutch 28. The solenoid 114 of the rotatingclutch valve 38 is normally closed, or normally low, to position thespool portion 110 of the rotating clutch valve 38 in the closed positionwith the rotating clutch 28 disengaged. The solenoid 114 of the rotatingclutch valve 38 increases fluid pressure in the rotating clutch signalline 116 when directed to engage the rotating clutch 28.

The lube regulator valve 42 includes a spool portion 120 that ismoveable between a first position, a second position and a thirdposition. The lube feed line 122 interconnects the feed line 54 of theprimary feed pressure line 48 and the lube regulator valve 42 forsupplying fluid to the lube regulator valve 42. A rotor supply line 124interconnects the lube regulator valve 42 with a rotor lubricationcircuit 126. The rotor lubrication circuit 126 circulates the fluidthrough a heat exchanger 128 to cool the fluid, through a gearbox 130 ofthe hybrid drive unit, and then through the rotor of each of the firstelectric motor 22 and the second electric motor 24 to cool and lubricatethe rotors. A regulated lube feedback line 132 interconnects the rotorsupply line 124 with an end of the spool portion 120 of the luberegulator valve 42. The regulated lube feedback line 132 provides fluidto the lube regulator valve 42 to bias against the spool portion 120 ofthe lube regulator valve 42. A stator supply line 136 interconnects thelube regulator valve 42 with a stator lubrication circuit 138. Thestator lubrication circuit 138 circulates fluid through the stator ofeach of the first electric motor 22 and the second electric motor 24 tocool the stators.

When the lube regulator valve 42 is in the first position, which isshown in the Figure, the spool portion 120 of the lube regulator valve42 opens fluid communication between the lube feed line 122 and therotor supply line 124, and closes fluid communication between the lubefeed line 122 and the stator supply line 136, thereby allowing the fluidat the line pressure to flow through the rotor lubrication circuit 126.When the lube regulator valve 42 is in the second position, the spoolportion 120 of the lube regulator valve 42 maintains fluid communicationbetween the lube feed line 122 and the rotor supply line 124, and opensfluid communication between the lube feed line 122 and the stator supplyline 136, thereby allowing the fluid to flow through the rotorlubrication circuit 126 and the stator lubrication circuit 138. When thelube regulator valve 42 is in the third position, the spool portion 120of the lube regulator valve 42 minimizes fluid communication between thelube feed line 122 and the rotor supply line 124 and opens fluidcommunication between the lube feed line 122 and the stator supply line136.

The lube regulator valve 42 is controlled by the lube boost solenoid142. The lube boost solenoid 142 may include any solenoid capable ofcontrolling the actuation of the spool portion 120 of the lube regulatorvalve 42. The primary feed pressure line 48 interconnects the pump 32with the solenoid 142 of the lube regulator valve 42. The solenoid 142of the lube regulator valve 42 utilizes an electrical signal from thehybrid drive unit controller or the vehicle controller to open and closefluid communication between the primary feed pressure line 48 and a lubeboost signal line 146. Accordingly, the lube regulator valve 42 is anelectronically controlled hydraulic valve.

The lube boost signal line 146 interconnects the solenoid 142 of thelube regulator valve 42 with a second end of the spool portion 120 ofthe lube regulator valve 42. The lube boost signal line 146 provides afluid pressure, which acts against the spool portion 120 of the luberegulator valve 42 to bias the spool portion 120 of the lube regulatorvalve 42 along with a lube regulator spring 148. The solenoid 142 of thelube regulator valve 42 controls the fluid pressure of the lube boostsignal line 146 to control movement of the spool portion 120 of the luberegulator valve 42 between the first position, the second position andthe third position. The solenoid 142 of the lube regulator valve 42 isnormally closed, or normally low, to prevent fluid communication betweenthe primary feed pressure line 48 and the lube boost signal line 146 andallow the lube regulator spring 148 to bias the spool portion 120 of thelube regulator valve 42 against the fluid pressure supplied by theregulator lube feedback line 132. The solenoid 142 of the lube regulatorvalve 42 opens and/or increases fluid communication between the primaryfeed pressure line 48 and the lube boost signal line 146 when signaledto move the spool portion 120 of the lube regulator valve 42 from thethird position or the second position into one of the second position orthe third position.

A lube bypass line 154 interconnects the primary feed pressure line 48and the lube feed line 122. The lube bypass line 154 includes apackaging protected orifice 156. Accordingly, if the pressure regulatorvalve 34 fails to open fluid communication to the lube feed line 122 toprevent excessive line pressures, the packaging protected orifice 156 iscapable of allowing fluid flow through the lube bypass line 154 toprovide limited lubrication and cooling to the electric motors 22, 24and the transmission components.

The detailed description and the drawings or figures are supportive anddescriptive of the invention, but the scope of the invention is definedsolely by the claims. While some of the best modes and other embodimentsfor carrying out the claimed invention have been described in detail,various alternative designs and embodiments exist for practicing theinvention defined in the appended claims.

1. A control system for controlling a hybrid drive unit of a vehicle,the control system comprising: a pressure regulator valve in fluidcommunication with a plurality of fluid lines and configured forregulating a line pressure of a fluid within the plurality of fluidlines; a first valve in fluid communication with at least one of theplurality of fluid lines and configured for opening and closing fluidcommunication between the plurality of fluid lines and a first clutch;and a second valve in fluid communication with at least one of theplurality of fluid lines and configured for opening and closing fluidcommunication between the plurality of fluid lines and a second clutch;wherein the first valve closes fluid communication between the pluralityof fluid lines and the first clutch to disengage the first clutch andthe second valve closes fluid communication between the plurality offluid lines and the second clutch to disengage the second clutch tooperate the hybrid drive unit in a first mode, the first valve opensfluid communication between the plurality of fluid lines and the firstclutch to engage the first clutch and the second valve closes fluidcommunication between the plurality of fluid lines and the second clutchto disengage the second clutch to operate the hybrid drive unit in asecond mode, the first valve opens fluid communication between theplurality of fluid lines and the first clutch to engage the first clutchand the second valve opens fluid communication between the plurality offluid lines and the second clutch to engage the second clutch to operatethe hybrid drive unit in a third mode, and the first valve closes fluidcommunication between the plurality of fluid lines and the first clutchto disengage the first clutch and the second valve opens fluidcommunication between the plurality of fluid lines and the second clutchto engage the second clutch to operate the hybrid drive unit in a fourthmode; and wherein the first valve and the second valve each include ashift valve characterized by a lack of a regulated pressure feedbackport.
 2. A control system as set forth in claim 1 wherein the firstvalve and the second valve are each characterized by the lack of apressure switch for indicating a clutch fill level.
 3. A control systemas set forth in claim 1 further comprising a third valve in fluidcommunication with the plurality of fluid lines and configured foropening and closing fluid communication between the plurality of fluidlines and a third clutch for engaging and disengaging the third clutchrespectively.
 4. A control system as set forth in claim 3 wherein thethird clutch includes a shift valve characterized by a lack of aregulated pressure feedback port.
 5. A control system as set forth inclaim 4 wherein the third valve is characterized by the lack of apressure switch for indicating a clutch fill level.
 6. A control systemas set forth in claim 3 further comprising a fourth valve in fluidcommunication with at least one lubrication circuit and the pressureregulator valve and configured for regulating a flow of the fluidbetween the pressure regulator valve and the at least one lubricationcircuit.
 7. A control system as set forth in claim 6 wherein thepressure regulator valve opens fluid communication with the fourth valvein response to the line pressure of the fluid reaching a pre-determinedlevel.
 8. A control system as set forth in claim 7 wherein the at leastone lubrication circuit includes a first lubrication circuit and asecond lubrication circuit.
 9. A control system as set forth in claim 8wherein the fourth valve continuously maintains open fluid communicationbetween the pressure regulator valve and the first lubrication circuit,and the fourth valve opens fluid communication with the secondlubrication circuit in response to the line pressure of the fluidreaching a pre-determined level.
 10. A control system as set forth inclaim 6 wherein the first valve, the second valve, the third valve andthe fourth valve each include an electronically controlled solenoid foractuating the first valve, the second valve, the third valve and thefourth valve respectively.
 11. A control system as set forth in claim 1further comprising an accumulator in fluid communication with the firstvalve and configured for damping fluid movement between the first valveand the first clutch.
 12. A control system as set forth in claim 1wherein the second clutch includes a rotating clutch and wherein thecontrol system further includes a compensator feed valve in fluidcommunication with the plurality of fluid lines and the second valve andconfigured for supplying the fluid to the second valve, with the secondvalve configured for directing the fluid to the rotating second clutchto provide a back pressure in the rotating second clutch when the secondvalve disengages the rotating second clutch.
 13. A valve body assemblyfor controlling a hybrid drive unit of a vehicle, the valve bodyassembly comprising: a pressure regulator valve in fluid communicationwith a plurality of fluid lines and configured for regulating a linepressure of a fluid within the plurality of fluid lines; a firstelectronically controlled hydraulic valve in fluid communication with atleast one of the plurality of fluid lines and configured for opening andclosing fluid communication between the plurality of fluid lines and afirst clutch, wherein the first electronically controlled hydraulicvalve opens fluid communication between the plurality of fluid lines andthe first clutch to engage the first clutch, and wherein the firstelectronically controlled hydraulic valve closes fluid communicationbetween the plurality of fluid lines and the first clutch to disengagethe first clutch; a second electronically controlled hydraulic valve influid communication with at least one of the plurality of fluid linesand configured for opening and closing fluid communication between theplurality of fluid lines and a second clutch, wherein the secondelectronically controlled hydraulic valve opens fluid communicationbetween the plurality of fluid lines and the second clutch to engage thesecond clutch, and wherein the second electronically controlledhydraulic valve closes fluid communication between the plurality offluid lines and the second clutch to disengage the second clutch; athird electronically controlled hydraulic valve in fluid communicationwith at least one of the plurality of fluid lines and configured foropening and closing fluid communication between the plurality of fluidlines and a third clutch, wherein the third electronically controlledhydraulic valve opens fluid communication between the plurality of fluidlines and the third clutch to engage the third clutch, and wherein thethird electronically controlled hydraulic valve closes fluidcommunication between the plurality of fluid lines and the third clutchto disengage the third clutch; and a fourth electronically controlledhydraulic valve in fluid communication with at least one lubricationcircuit and the pressure regulator valve, and configured for regulatinga flow of the fluid between the pressure regulator valve and the atleast one lubrication circuit; wherein the first valve disengages thefirst clutch and the second valve disengages the second clutch tooperate the hybrid drive unit in a first mode, the first valve engagesthe first clutch and the second valve disengages the second clutch tooperate the hybrid drive unit in a second mode, the first valve engagesthe first clutch and the second valve engages the second clutch tooperate the hybrid drive unit in a third mode, and the first valvedisengages the first clutch and the second valve engages the secondclutch to operate the hybrid drive unit in a fourth mode; wherein thefirst valve, the second valve and the third valve each include a shiftvalve characterized by a lack of a regulated pressure feedback port; andwherein the first valve, the second valve and the third valve are eachcharacterized by the lack of a pressure switch for indicating a clutchfill level.
 14. A valve body assembly as set forth in claim 13 whereinthe pressure regulator valve opens fluid communication with the fourthvalve in response to the line pressure of the fluid reaching apre-determined level.
 15. A valve body assembly set forth in claim 13wherein the at least one lubrication circuit includes a firstlubrication circuit and a second lubrication circuit.
 16. A valve bodyassembly set forth in claim 15 wherein the fourth valve continuouslymaintains open fluid communication between the pressure regulator valveand the first lubrication circuit, and the fourth valve opens fluidcommunication with the second lubrication circuit in response to theline pressure of the fluid reaching a pre-determined level.
 17. A valvebody assembly set forth in claim 13 wherein the first valve, the secondvalve and the third valve each include an on/off solenoid.
 18. A valvebody assembly set forth in claim 13 further comprising an accumulator influid communication with the first valve and configured for dampingfluid movement between the first valve and the first clutch.
 19. A valvebody assembly as set forth in claim 13 further comprising a compensatorfeed valve in fluid communication with the plurality of fluid lines andthe second valve and configured for supplying the fluid to the secondvalve, with the second valve configured for directing the fluid to thesecond clutch to provide a back pressure in the second clutch when thesecond valve disengages the second clutch.